As part of an ongoing campaign attacking the credibility of journalist Gabriel Sherman, who is writing a forthcoming book about Fox News, Breitbart.com accused him of violating the privacy of network president Roger Ailes' family. After the story's publication, Sherman received a violent threat from one of the site's readers.

Writing at Breitbart.com, Celia Bigelow claimed that Sherman, a New York magazine reporter who has broken a number of stories about Fox News and is the author of a forthcoming book on the network, is writing a "hatchet-job biography" about Roger Ailes. According to Bigelow, Sherman has "reportedly has been observed violating the privacy not only of Ailes himself but also of the Ailes family."

Bigelow also wrote that Sherman "has been seen many times snooping around Putnam County, NY, where the Ailes family maintains a weekend home" and accuses him of "targeting" Ailes' wife. She concludes that Sherman "has crossed the line -- the honor-code line, that is."

Bigelow offered little evidence to back up her claims about Sherman, only a tweet in which Elizabeth Ailes complains about Sherman following her on Twitter -- a public forum.

After the story was posted, Sherman quotedanemail he had been sent that told him to "stop the stalking" and that he should "stop harassing the Ailes family." The letter continued, "as a combat Marine I sure hope I would control my impulsive behavior. You sir have no self discipline. We will be watching you."

This isn't the first time Breitbart.com has attacked Sherman for his reporting on Fox and Ailes. Months ago, the outlet warned readers that he was "going to go after Ailes, big time" and accused him of "deliver[ing] the good for his lefty paymasters."

Another story used an anonymous source to describe Sherman as "Jayson Blair on steroids," comparing him to the former New York Times reporter who fabricated several stories for that publication. That story also claimed that Sherman's position as a fellow at the New America Foundation made him beholden to "masters such as [George] Soros and the other liberals who fund" it.

As The Washington Post's Erik Wemple reported, Ailes is working with Fox contributor Jim Pinkerton to write his autobiography, and Pinkerton was a fellow at the same New America Foundation "off and on" from 2000 to 2009.

In February, Ben Shapiro and Stephen K. Bannon wrote a Breitbart.com story that claimed Sherman was "losing ground to others" in reporting on Fox News.

At least one Fox personality has directly participated in attacks on Sherman. As Bigelow noted in her piece, Fox host Andrea Tantaros accused Sherman of being part of the "stalker media" and a "harasser."

In his recent book about Ailes, Zev Chafets writes that Ailes coordinated a smear campaign against Media Matters in order to counteract the publication of the book The Fox Effect, seeing to it that "friendly websites and some Fox commentators" promoted negative stories about the organization.

Fox hosts have lavished praise on Chafets' book, which was written with the full cooperation of Ailes, reportedly to help counter Sherman's book.